WASHINGTON -- House Speaker Nancy Pelosi sought on Thursday to create a special committee in an effort to jump-start long-delayed government efforts to deal with global warming and produce a bill by Independence Day.

Pelosi, D-Calif., said she would ask the House for a vote to set up the committee. She wants it to hold hearings and recommend legislation on how to reduce greenhouse gases, primarily carbon dioxide generated by fossil fuels, that most scientists blame for a gradual warming of the earth's climate.

Existing committees that deal with energy, environment and technology would be asked to draft bills based on the global warming committee's recommendations.

"The science of global warming and its impact is overwhelming and unequivocal," Pelosi said in a statement. "With this new select committee, we demonstrate the priority we are giving to confront this most serious challenge. Now is time to act. The future of our country, indeed our entire planet, is at stake."

Pelosi set a goal of the Fourth of July for finishing a global warming bill that would "truly declare our energy independence."

The committee will be led by Rep. Ed Markey, D-Mass., who shares Pelosi's goals, said a Democratic leadership aide, speaking on condition of anonymity because Pelosi had yet to announce her choice.

Pelosi's move increases the likelihood that Democrats will propose far tougher constraints on greenhouse gas pollution than the Bush administration wants. She also has outflanked for now -- and angered -- a few Democrats who head important House committees.

"We should probably name it the committee on world travel and junkets," said Rep. John Dingell, D-Mich., chairman of the House Energy and Commerce Committee, which oversees the Clean Air Act and the Environmental Protection Agency.

"We're just empowering a bunch of enthusiastic amateurs to go around and make speeches and make commitments that will be very difficult to honor," said Dingell, a champion of the auto industry, which could be required to producing cleaner-burning and more fuel efficient vehicles.

Dingell, the House's longest-serving member at age 80, long has viewed environmental legislation as being his domain.

"They're going to get under the feet of and interfere with those who are trying to do a decent job of legislating," Dingell said in an interview with The Associated Press. "I'm unaware of anything they will do that will be of any value."

Reminded that Markey was one of his proteges, Dingell replied: "I won't be able to help him on this undertaking, now will I?"

Dingell convened Democratic members of his committee for two hours of private talks Wednesday. He said they agreed to send a delegation to meet with Pelosi and iron out who controls what.

"We're all jealous of our jurisdiction," Rep. Gene Green, D-Texas, said after the meeting.

Rep. George Miller, D-Calif., said the new committee builds pressure on the Bush administration, Dingell's panel and other members of Congress. It creates "an opportunity to go from denial into what needs to be done in the future," he said.

Ways and Means Committee Chairman Charles Rangel, D-N.Y., withheld judgment until he learned more. Rangel would have jurisdiction on any tax legislation aimed at affecting industry behavior on the environment.

"The appointees are totally unknown," he said. "I understand that they will have no legislative authority."

Environmentalists hailed Pelosi's decision as a momentum-builder to challenge the administration.

"This is a really gutsy move by the speaker," said Philip Clapp, president of National Environmental Trust. "Action on global warming is so urgent that the speaker has probably taken the only course that could produce a comprehensive bill before the 2008 elections swamp the political process."